What would happen if we could see a red thread connecting a couple who are destined to meet each other? Kaori, Hikari, and Natsume are childhood friends, and each of them is a different type of person. The three obtained a mysterious medicine that would enable them to see such a red thread that would influence their destinies. Though they found it difficult to believe, they tried anyway. Besides "Pinky Labyrinth," two complete stories are collected.